Salesforce licenses

HI,

I'm struggling to get the best choice for me in terms of kind of license I need. I just want to connect my website using chatter through OAuth2 as well as I have been developing a canvas app. Everything has been done with my developer account in Salesforce but I have been wondering if I need to purchase any kind of license to use it. Even I have been wondering if I need a new license to upload my canvas app to salesforce app exchange.

I will be really grateful if someone could tell me something about it because I don't really know what I should do due to salesforce licenses are expensive.